15–19 Jun 2026
Dipartimento di Fisica G. Occhialini, Università Degli Studi di Milano-Bicocca
Europe/Zurich timezone

The morphology of fluorescent emission from the intergalactic medium as a probe of dark matter properties

16 Jun 2026, 16:50
20m
U3-01

U3-01

Oral contribution Topical Session 1 - Astro

Speaker

Titouan Lazeyras (University of Milano-Bicocca)

Description

While the existence of dark matter is well established, its precise properties remain a pivotal question of modern cosmology. In this talk, I will present a new probe to constrain dark matter properties: fluorescent emission from the intergalactic medium around UV-bright quasars in the young universe (z~3). The gas in the intergalactic medium is an optimal tracer of the underlying dark matter, but its low surface brightness makes it challenging to observe. UV-bright quasars represent a particularly favorable environment as they can ionize their surrounding gas which can then be observed through its recombination emission, particularly at the Lyman-alpha frequency. In the recent years, new, more sensitive instruments, such as MUSE on the VLT, have delivered for the first time observations of this emission extending several Mpc from the central objects. I will first introduce our new suite of hydrodynamical simulations used to create mock observations in different dark matter scenarios. I will then show that the morphology of the Lyman-alpha emission is impacted by dark matter properties, and that the differences happen at surface brightness levels observable by current instruments with moderate to deep exposure times. These results constitute the first steps towards new constraints on the nature of dark matter complementary to, and competitive with existing ones.

Parallel session Astrophysical Probes of Dark Matter and Dark Energy

Author

Titouan Lazeyras (University of Milano-Bicocca)

Presentation materials

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